Module: Sinatra::API::Parameters

Defined in:
lib/sinatra/api/parameters.rb

Overview

API for defining parameters an endpoint requires or accepts, their types, and optional validators.

TODO: accept nested parameters

Instance Method Summary collapse

Instance Method Details

#api_clear! ⇒ Object Also known as: api_reset! 



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# File 'lib/sinatra/api/parameters.rb', line 137

def api_clear!()
  @api = { required: {}, optional: {} }
end

#api_consume!(keys) ⇒ Object

Consumes supplied parameters with the given keys from the API parameter map, and yields the consumed values for processing by the supplied block (if any).

This is useful if:

  1. a certain parameter does not correspond to a model attribute and needs to be renamed, or is used in a validation context
  2. the data needs special treatment
  3. the data needs to be (re)formatted


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# File 'lib/sinatra/api/parameters.rb', line 89

def api_consume!(keys)
  out  = nil

  keys = [ keys ] unless keys.is_a?(Array)
  keys.each do |k|
    if val = @api[:required].delete(k.to_sym)
      out = val
      out = yield(val) if block_given?
    end

    if val = @api[:optional].delete(k.to_sym)
      out = val
      out = yield(val) if block_given?
    end
  end

  out
end

#api_has_param?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sinatra/api/parameters.rb', line 118

def api_has_param?(key)
  @api[:optional].has_key?(key)
end

#api_optional!(args, h = params) ⇒ Object

Same as #api_required! except that fields defined in this map are optional and will be used only if they're supplied.

See Also:



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# File 'lib/sinatra/api/parameters.rb', line 68

def api_optional!(args, h = params)
  args.each_pair { |name, cnd|
    if cnd.is_a?(Hash)
      api_optional!(cnd, h[name])
      next
    end

    parse_api_argument(h, name, cnd, :optional)
  }
end

#api_param(key) ⇒ Object 



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# File 'lib/sinatra/api/parameters.rb', line 122

def api_param(key)
  @api[:optional][key.to_sym] || @api[:required][key.to_sym]
end

#api_params(q = {}) ⇒ Object

Returns a Hash of the supplied request parameters. Rejects any parameter that was not defined in the REQUIRED or OPTIONAL maps (or was consumed).

Parameters:

  • q (Hash) (defaults to: {}) —

    A Hash of attributes to merge with the parameters, useful for defining defaults.



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# File 'lib/sinatra/api/parameters.rb', line 133

def api_params(q = {})
  @api[:optional].deep_merge(@api[:required]).deep_merge(q)
end

#api_required!(args, h = params) ⇒ Object

Note:

The supplied value passed to validation blocks is not pre-processed, so you must make sure that you check for nils or bad values in validator blocks!

Define the required API arguments map. Any item defined not found in the supplied parameters of the API call will result in a 400 RC with a proper message marking the missing field.

The map is a Hash of parameter keys and optional validator blocks.

Each entry can be optionally mapped to a validation proc that will be invoked if the field was supplied. The proc will be passed the value of the field.

If the value is invalid and you need to suspend the request, you must return a String object with an appropriate error message.

Examples:

A map of required API call arguments

api_required!({ title: nil, user_id: nil })

Rejecting a title if it's rude

api_required!({
  :title => lambda { |t| return "Don't be rude" if t && t =~ /rude/ }
})


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# File 'lib/sinatra/api/parameters.rb', line 53

def api_required!(args, h = params)
  args.each_pair do |name, cnd|
    if cnd.is_a?(Hash)
      api_required!(cnd, h[name])
      next
    end

    parse_api_argument(h, name, cnd, :required)
  end
end

#api_transform!(key, &handler) ⇒ Object 



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# File 'lib/sinatra/api/parameters.rb', line 108

def api_transform!(key, &handler)
  if val = @api[:required][key.to_sym]
    @api[:required][key.to_sym] = yield(val) if block_given?
  end

  if val = @api[:optional][key.to_sym]
    @api[:optional][key.to_sym] = yield(val) if block_given?
  end
end

#parse_api_argument(h = params, name, cnd, type) ⇒ Object (private) 



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# File 'lib/sinatra/api/parameters.rb', line 145

def parse_api_argument(h = params, name, cnd, type)
  cnd ||= lambda { |*_| true }
  name = name.to_s

  unless [:required, :optional].include?(type)
    raise ArgumentError, 'API Argument type must be either :required or :optional'
  end

  if !h.has_key?(name)
    if type == :required
      halt 400, "Missing required parameter :#{name}"
    end
  else
    if cnd.respond_to?(:call)
      errmsg = cnd.call(h[name])
      halt 400, { :"#{name}" => errmsg } if errmsg && errmsg.is_a?(String)
    end

    @api[type][name.to_sym] = h[name]
  end
end